Hydrogen-Induced Lattice Rearrangements in Alloys

这项研究探讨了吸收的氢原子对 金属合金中的相变 溶解的氢似乎 提高金属原子的迁移率，并允许相分离， 通常在较低温度下观察到。 氢诱导晶格 因此，移动性（HILM）是该计划的主题。 使用 以钯铑合金体系为模型， 组成作为氢含量的函数来确定。 氢气在高压下引入（高达2000 大气压）。 结合HILM的相分离研究是 扩展到钯-铂和镍-铜合金系统。 HILM诱导的金属间相的有序性在 在这些合金系统中选择金属间化合物。 分析 电子探针分析和扫描等技术 透射电子显微镜被用来表征 发生的阶段和相关变化。 HILM的机制是 基于开发的实验数据进行考虑。 %%% 这项研究的结果应该澄清如何使用HILM 有效地应用于相图测定、材料 合成和微合金化。

This research explores the effects of absorbed hydrogen atoms on phase changes in metal alloys. Dissolved hydrogen appears to enhance metal atom mobility and allows phase separation not normally observed at lower temperatures. Hydrogen-induced lattice mobility, (HILM) is, therefore, the subject of this program. Using the palladium-rhodium alloy system as a model, phase boundary compositions are determined as a function of hydrogen content. Hydrogen is introduced under high pressures (up to 2000 atmospheres). Phase segregation studies incorporating HILM are extended to the palladium-platinum and nickel-copper alloy systems. HILM-induced ordering of intermetallic phases is examined in selected intermetallics in these alloy systems. Analytical techniques such as electron microprobe analysis and scanning transmission electron microscopy are employed to characterize the phases and related changes that occur. Mechanisms of HILM are considered based on the experimental data developed. %%% Results from this research should clarify how HILM can be used effectively in such areas as phase diagram determination, materials synthesis, and micro-alloying.